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Smoking Engine

marcum03's Avatar
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05-15-05, 11:31 AM   #1  
Smoking Engine

I was given a 12.5HP Briggs short block engine. It was locked up in the cylinder. I managed to take it apart & free the piston. after examining it, it looked repairable. I cleaned all the parts & piston, & put in rings from a different engine of the same type, then honed out the cylinder (no damage, only bad carbon deposits). I wanted to know if it will run before putting any more money into it. I didn't remove any valves, just cleaned cabon deposits around it the best I could. then put it all back together.

I started it up & it runs & sounds really smooth with lots of compression & power, I cut all my grass with no problem at all, but it smokes like a freight train.

What do I need to do or replace in order to stop the smoke?

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cheese's Avatar
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05-15-05, 11:12 PM   #2  
It depends. If the cylinder has any scratches to speak of in it, then it won't stop. Rings normally stop the smoking if the cylinder is ok. Proper cross-hatch honing pattern is also needed to properly seat the rings.

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puey61's Avatar

Join Date: Apr 2004
Posts: 3,224

05-16-05, 03:24 AM   #3  
On a flat head engine, the three areas that would cause an oil smoking situation are: 1- Worn cylinder; acurately measure to determine if it would need to be bored oversize. 2- If the cylinder is within specs then worn rings; place each ring a 1/4" in the cylinder bore and check the endgap. 3- Sloppy valve guides; check for side play of each valve while in the full open position.

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